The directors of Marvel's latest blockbuster say chances of the franchise's films introducing more LGBT characters are "strong".

In an interview with Collider, Captain America: Civil War directors Joe and Anthony Russo said it was their responsibility to reflect their quickly diversifying audience.

The pair, who will also head Marvel's upcoming two-part saga Avengers: Infinity War, said "it's incumbent upon us as storytellers" to make mass-appeal movies which actually have mass appeal.

David Betancourt: Iron man? No, here's why Captain America is Marvel's most important Avenger franchise
Doctor Strange shows why we should take Chinese censorship seriously


"It's sad in the way that Hollywood lags behind other industries so significantly, one because you think that it would be a progressive industry, and two it's such a visible industry. So I think it's important that on all fronts we keep pushing for diversification because then the storytelling becomes more interesting, more rich, and more truthful," they told Collider.

Anthony Russo added that the success of Marvel as a franchise made it easier to make these kinds of changes.

Video will play in
Play now
Don't auto play

Never auto play
The latest trailer for Marvel’s Captain America: Civil War.

Marvel Studios has consistently produced one box office hit after another; each of their films since the release of The Avengers in 2012 have grossed more than US$500 million ($739 million) worldwide, and two of them - Iron Man 3 and Avengers: Age of Ultron - surpassed US$1 billion.

"I think this is a philosophy of Marvel, in success it becomes easier to take risks ... So I think that's very hopeful for all of us moving forward that bolder and bolder choices can be made," Russo said.

And the material for it is there; Marvel's expansive catalogue of comic characters had dozens upon dozens of lesser-known heroes and villains who all identify as LGBT.

And in the realm of better-known LGBT characters, many of them have already seen some screen time; X-Men's Mystique and Jessica Jones' Hogarth topping the list, though Hogarth is the only one to identify on-screen.

There are also alternate-universe versions of characters like Spiderwoman, Beast and Mr Fantastic who identify as LGBT in Marvel's comics.